Core blower



Dec. 8, 1953 R. N. BREWER 2,661,513

CORE BLOWER Filed Au 50, 1951 IN V EN TOR.

fiE/fe fY. Brewer BY Mai M M his zzarneys Patented Dec. 8, 1953 UNITED sTAT E s. PAT orrlcs Relfe N. Brewerf lfni:r: n?::fassignor ,m, Gen;

eral Motors Corporation, DetroitgMich -a cor.- porafion ofDelawareAppIicationAugust130, iesig ser iamol 244,411

1 Claim. (.01.. 32-

, 1 Thi'siinvention relates, 'toa coreblower used to blow sand into a"core mold which is inaccessible for tamping.

It is, therefore, the main object of the invention to provide a coreblower which will uniformly eject a core sand mixture therefrom into acore mold.

A further object of the invention is to provide a core blower comprisingan elongate tube having a predetermined inner diameter with an outlet atone end thereof to form a chamber, which may be filled with a core sandmixture. An upper attachment cap including an air nozzl is provided,which air nozzle emits pressurized air into the chamber in a directionhorizontal to th main axis of the chamber whereby said mixture isuniformly forced into the outlet without channelling.

Further objects and advantages of the present invention will be apparentfrom the following description, wherein reference is made to theaccompanying drawing, which shows in section a core blower in place onthe core mold.

In the manufacture of cores for use in the casting of metals, core sandis mixed with molasses or some other suitable adhesive material and isplaced in core molds and baked in order to form a baked sand core whichmay then be used to core out articles to be subsequently cast frommetal. A distinct problem in the manufacture of baked sand cores is touniformly fill molds which include reentrant angles therein, it beingvery diflicult to tamp the core sand mixture into the mold uniformlywhereby the baked cores are nonuniform and often crumbly due to the factthat the density of the mixture as placed in the mold is non-uniform.

For this purpose, it is desirable to have a core sand blower wherein themolds are filled under pressure, which provides greater uniformitytogether with reduced production cost.

In order to provide a satisfactory core blower, it is necessary todesign the apparatus so that the core sand mixture placed in the bloweris uniformly emitted therefrom without channelling and the like, sinceit is quite apparent that if the mixture is channelled due tonon-uniform pressure, the portion remaining in the blower hardens and isnot as easily fiowable as other portions thereof, whereby non-uniformityis the obvious result.

In order to accomplish the ends desired, I have designed a core blower20 shown in the drawing as assembled to a core mold 2| having a cavity23 therein which is to be filled with core sand. The

blower; 24! consists of an elongate tubularmember 2:25 which providesaeavity .24 therein. .At the upper end of the member 22 there is a cap26 which is locked to the tube 22 through any suitable means such asbayonet joint shown at 28. The cap 26 includes a fitting 30 threadedtherein which is attached at its outer end by a tube 32 to a pressuresource such as a compressor or the like. It is apparent that valvemeans, not shown, may be provided in the pressure tube 32 forcontrolling the action of the device. The fitting 30 is hollowed out at34 and this portion of the fitting extends into the cavity 24. Thislower portion has a plurality of apertures 36 spaced around the verticalwalls thereof. In other words, pressurized air which is emitted from thefitting 30, passes in a direction perpendicular to the longitudinal axisof the cavity 24. Thus the upper portion of the cavity 24 i pressurizedwhereby sand therein is forced through the outlet opening 38 at theopposite end thereof into the cavity 23. The outlet 38 is merely anapertur in the tapered end of the tube 22, which end is tapered toprovide satisfactory flow of sand and likewise to permit an easyattachment to the core mold orifice.

The direction of air emission from the fitting 30 is important to thesuccess of the invention. If an aperture were provided in the end of thefitting 30, the pressurized air would tend to channel the sand, therebyforcing the center portion of the sand held in the cavity 24 through theoutlet 38 while permitting the remainder of the charge to stay in theblower cavity 24. Obviously, if the sand mixtur includes a binder, thiswill tend to become dried out in view of the constant passage of airthereover, making the mixture of different flow characteristics wherebynon-uni formity would be apparent in the cores. Also, it would beimpossible to empty the cavity 24 of the sand therein, thereby causingconsiderable waste or necessitating mixing the remaining sand in thecavity with an additional charge in order to obtain a full cavity.

By having the orifices 36 perpendicular to the longitudinal axis of thecavity 24, the pressurized air in effect acts as a piston over thecharge in said cavity 24 and uniformly forces the entire chargedownwardly through the outlet 38.

Specifically, a core blower 10" long is preferably provided with aninternal cavity diameter of about 1%. This diameter is of someimportance since if the diameter is much greater than 1%", the pistoneffect of the air charge is lost. The specific length of the cavity isnot too important but the diameter is a definite limitation which mustbe adhered to if satisfactory operation is to be obtained. For thesereasons, a limit of the diameter of the core blower cavity to a diameternot greater than 1%" is necessary with the design shown, it being aproven fact that when the diameter of the cavity exceeds this figure,channelling becomes apparent and the core blower is of little usecommercially.

While the embodiments of the present invention as herein disclosed,constitute preferred forms, it is to be understood that other forms YReferences Cited in the file of this patent might be adopted.

What is claimed is as follows:

A core blower for use in filling core molds, comprising in combination;an elongate charging tube having an unrestricted internal diameter notin excess of 1 /2", open atone end and having 7.

an outlet orifice at the other end thereof,v a removable cap for saidtube for closing the open end ting being closed at its inner end andincluding a plurality of radially located apertures in the extended wallthereof, said fitting being adapted to have the other end connected to asource of fluid pressure whereby fluid under pressure will enter saidfitting and be directed into the tube perpendicularly to thelongitudinal axis thereof so as to force the contents of the chargingtube longitudinally wtihout channeling into a core mold.

RELFE N. BREWER.

UNITED STATES PATENTS Number Name Date 1,563,156 Burman Nov. 24, 1925,1,910,417 Zeman May 23, 1933 2,556,618 Harrison et al June 12, 1951FOREIGN PATENTS Number Country Date 601514 Great Britain May 11, 1948

